A roller bearing assembly generally of the type to which the present invention relates is shown in West German Pat. No. 371,438. The bearing assembly shown in this patent comprises a pair of so-called barrel rings, each having a raceway held together by annular fastening members on the lateral outer surface and in the bore. In the preferred arrangement shown in the German patent, an annular spacer member is provided between the adjacent side-by-side inner rings. By reason of this type of design, it is possible to manufacture the barrel rings separately, which is particularly advantageous in large-size bearing assemblies. Fastening and spacer members are necessary to form a roller bearing assembly ready for installation which provides additionally a compact unit for ease of transportation. In order to exploit these advantages, many accessory parts and the corresponding effort to assemble them are required in the presently known designs. Additionally, the two-part fastening sleeve which engages over the lateral surface represents an additional part subject to tolerances which must be produced with a high level of precision to ensure the necessary conditions for installation of the known roller bearing unit into a prefabricated seating bore. Additionally, the plural seating surfaces arrange successively in a radial direction in the lateral surface area present a situation which encourages defective installation or leads to changes in the accuracy of the seating during operation.
With the foregoing in mind, it is therefore an object of the present invention to provide a double-row ball bearing assembly which is assembled from separate rings whose peripheral surfaces, in the installed state, cooperate directly with corresponding seating surfaces to form a relatively compact unit which resists falling apart. To this end, the spacer member located between the barrel rings prevents the barrel rings from moving axially outwardly by reason of a form-locking connection provided by the rolling elements. Specifically, the spacer member has projections on both sides which cooperate with the associated barrel rings and the fastening member is provided on the other corresponding barrel ring. The roller bearing assembly of the present invention consists broadly of separately manufactured barrel rings which are maintained in assembled relation by at least one annular fastening member and an annular spacer member to form a double-row design. The fastening member holds together one pair of cooperating barrel rings and the spacer is located between the other pair of corresponding barrel rings. This division forms the optimum roller bearing arrangement according to the present invention which provides the fundamental solution to the problems of the prior art noted above. The principle of the present invention can be utilitized in other types of roller bearing arrangements simply by utilizing additional fastening members and additional spacers. Moreover, the beneficial effects provided by the present invention are applicable to other types of bearings such as double-row, purely radial load-bearing designs with ball or roller bearings or to angular contact bearings in an X or O configuration. The spacer for a bearing design in accordance with the present invention is adapted to be mounted between the barrel rings which, because of the positive locking connection by way of the raceways and the rolling elements, cannot move axially outwardly. In a roller bearing assembly designed for radial load exclusively, these are, for example, the outer barrel rings, provided that they have axially inwardly facing shoulders or flanges. In roller bearing assemblies of the O-configuration, these are again the outer barrel rings, whereas in the X-configuation, the spacer is provided between the inner rings. It is noted, however, that in all of the various modifications and alternatives discussed above, the principle is the same; that is, the barrel rings with no freedom of outward axial movement are provided with a spacer and rings free to move axially outwardly are provided with the fastening member.
Considering now the specific features and details of the present invention, the fastening member can be located in the area of the bore or lateral surface of the roller bearing assembly depending on which of the bearing configurations mentioned above is being utilized. Annular recesses are provided to keep the fastening member away from the seating surface. The spacer may be provided with axial projections which complement and cooperate with the rounded edges of the barrel rings to fix the same in a radial direction. In the foregoing, it can be seen that the present invention requires two relatively simple and easily manufactured components which, with the separately manufactured barrel rings and rolling elements, forms a double-row roller bearing assembly which is retained integral as a unit and cannot fall apart.
Other more specific features of the present invention include the provision of a one-piece spacer element of T-shaped profile which define profile sections projecting on both sides into the bearing spaces.
The present invention also contemplates alternative designs for the spacer and the means for securing it in radially form-locking installation between the rings. These spacer designs include axial projections or the like extending on both sides into the bearing space which rest preferably against the associated peripheral surface of the barrel rings. In this manner, the spacer and the barrel rings are fixed radially in a form-locking manner, the former with respect to the barrel rings and the barrel rings with respect to each other. More specifically, in accordance with one embodiment of spacer, the spacer is made of a single unitary piece and has a T-shaped profile defining profile sections projecting on both sides into the bearing spaces. Alternatively, the spacer may be provided with a rectangular profile with at least three axial holes distributed around the periphery for pins which project out on both sides into the bearing space. Further, the rectangularly profiled spacer may include on the associated peripheral surface a frictionally connected sleeve, the edges of which project on both sides into the bearing spaces. The edges of this sleeve can be bent over to form flanges which rest against the end surfaces of the spacer.